TIPS TO REMOVE PAPER TEXTURE FROM OLD PHOTOS
Minimising or removing the paper texture inherited when scanning an old photo is often one of the challenges photo restoration newbies find time-consuming under conventional methods.
However, some useful methods and algorithms help to minimise or even get rid of patterns and textures prevalent in vintage photographic papers, (especially those used in the late ’70s.)
However, if you are scanning the photo in-house or plan to restore it yourself, find below a few tips to assist you in achieving better results.
1. CHECK FOR THE PHOTO NEGATIVE
Let’s start from the basics, perhaps you or your family member still has he photo negative around. Removing the texture from an old photo is not such an easy task, so if you can take your time to search for the film, you will be saving yourself hours of digital photo restoration.
We are often asked if it is better to scan from negatives rather than from printed photos, and the short answer is: “it depends” anyhow to remove those nasty patterns from a photo negative are the way to go.
However it is vital to assess the condition of a negative, the decision criteria should be to save you time and effort so judge based on the status of both sources,
We have found that sometimes hybrids are an excellent way to obtain detail when both negatives and prints are damaged.
So, checking around for other sources is a good photo restoration practice but also an activity that can connect you with your family history and an opportunity to find other treasures or memories lost in time.
2. SCAN THE PHOTO FOUR TIMES.
Scanning the photo four times but in a different angle is one of the oldest tricks in the book, but still, an excellent way to get the most out of your textured photograph print when home scanning.
Just scan the first time and once the process is complete rotate the photo 90 degrees on the flatbed and scan again using the same settings, repeat this procedure until you have the photo scanned four times in further 90 degree angles.
A best practice is to turn off any auto adjustments such as auto-exposure and auto-levels so you can have more control during the scanning process.
Once we finalise the photo digitalisation, we can combine the four photos in photoshop and use a darken blending mode to get rid of the highlights, which are indeed the problem.
Why? just because despite your scanner quality the light will unavoidably bounce and reflect in a different angle when reaching the texture; therefore each scan will be slightly different and once combined the surface pattern will be minimised. (unfortunately not wholly removed in many cases but worth a try)
3. FFT FILTER (FAST FOURIER TECHNIQUE)
An advanced technique to perform photo pattern suppression is using FFT filters, and some FFT algorithms are compelling when processing and interpreting patterns in photographs, to the point that is a weapon of choice to complex activities such as reverse forensic photography analysis.
This technology is available today to a certain extent for post-photography processing, and it’s advantageous,
Finding and extracting textures, fingermarks, patterns and noise signals from a photograph has never been easier thanks to partially automated processing and professional input when dealing with a photo and interpreting its signal-to-noise ratio.
FFT algorithms and Photoshop techniques such as frequency separation and channel blending are successful strategies to identify, reduce or even remove unwanted textures from old photographs.
However, these strategies have a considerable dependency on human input and analysis.
FFT processing is unique in its capacity to identify, optimise and reverse engineer the image signal to noise ratio by suppressing the obstructive patterns and separating frequencies effectively.
Using an FFT equation filter or algorithm to find regular patterns can successfully assist in finding and then reversing the pattern equations and are the best tool available today to the public.
To know more about FFT or download the plugin/filter freeware follow this link FFT Fast Fourier Transform and pattern suppression
4. FREQUENCY SEPARATION
Another pattern suppression technique that can assist in separating textures and background is Frequency Separation, (basically an inverted high-pass)
This process consists decomposing of the image data into different layers so that we can edit image components in the different frequencies independently by subtracting its elements based on the frequency rate of the pixels.
Therefore we can edit the noise in the foreground and the background fill in the background, this is quite useful to perform patching and healing without compromising tonalities and obtaining shades of colour evenly without interfering with the texture.
For more information on Frequency, separation check on this cool youtube video by PHLEARN.
CHOOSE YOUR PATTERN SUPPRESSION TECHNIQUE
We can remove or minimise repetitive patterns using Adobe Photoshop and a selection of plugins, filters and actions that will let us quickly, and with unparalleled quality, remove periodical repeating patterns from images.
However, photo restoration requires the audacity of knowing the best pathway to take, when in a Photoshop workflow, you can achieve excellent results using a ton of different process.
Our recommendation is to take your time and assess the damage or restoration requirements thoroughly before starting any works, this way you can save yourself some time, avoid getting stuck and achieve the best possible outcome.
IS THERE AN FFT (FAST FOURIER TRANSFORM) FILTER FOR MAC?
There are excellent FFT filter software. plugins or actions to remove or suppress repetitive patterns for PC but unfortunately the ones existing on a Macintosh platform are limited, require an special installation or simply old, however even though some can be quite technical to run, we can list a few applications or extensions that you might consider to give it a try:
Have you tried these plugins before or do you know another plugin that can assist the restoration community speeding up this workflow, contact us at [email protected] and tell us about your experience.